Field of the Invention
The disclosure relates to a method for generating a reference voltage and, more specifically, to a method and an electronic device for generating a reference voltage which is regulated dynamically cooperating with an overclocking operation.
Description of the Related Art
Generally, when a computer boots, reference voltages are generated to provide power for internal components. A CPU (Central Processing Unit) requires different operating voltages according to different operating frequencies. Generally, the CPU outputs a voltage identification signal (SVID) to a VRM (Voltage Regular Module) via a voltage identification (VID) pin. Then, the VRM looks up a pre-determined voltage corresponding table to find a required voltage value corresponding to the voltage identification signal, and provides an appropriate reference voltage to the CPU.
FIG. 1 is a schematic diagram showing relationship between a reference voltage and an operating frequency. Referring to FIG. 1, the vertical axis represents the reference voltage VREF provided by the VRM, and the horizontal axis represents the operating frequency F of the CPU. According to the voltage identification signal input from the CPU, the VRM provides the reference voltage VREF corresponding to the operating frequency F. The correspondence relationship between the reference voltage VREF and the operating frequency F is represented by a curve C1 in FIG. 1.
As shown in the curve C1, if the operating frequency F reaches to an overclocking frequency FOC (an operating frequency when a computer overclocks), a conventional VRM maintains the reference voltage VREF at a high constant value VH, but not provides a higher operating frequency F, which restricts the efficiency of the CPU at overclocking. Similarly, if the operating frequency F decreases to a low frequency FL, the VRM maintains the reference voltage VREF at a low constant value VL, which may be excessive for the operation of the CPU to cause power consumption.